한국고유종 남방종개 Iksookimia hugowolfeldi (미꾸리과)의 난발생 및 초기생활사

Egg Development and Early Life History of the Korean Southern Spine Loach, Iksookimia hugowolfeldi (Pisces: Cobitidae)

한국 고유종 남방종개 Iksookimia hugowolfeldi의 난발생 및 초기생활사를 밝히기 위하여 조사를 실시하였다. 성숙한 개체 복강에 Ovaprim (0.5 mL/kg)을 주사하여 12시간 경과 후 복부 압박법으로 채란하여 건식법으로 인공수정 시켰다. 산란된 난은 평균 $1,933{\pm}530$개로, 약한 점착성을 띤 밝은 노란색의 분리침성난이었으며, 난경은 $1.35{\pm}0.03mm$였다. 수온 $25^{\circ}C$에서 수정 후 56시간(50%)에 부화하였으며, 크기는 전장 $5.6{\pm}0.18mm$였다. 부화 후 5일에는 전장 $7.8{\pm}0.31mm$로 난황을 모두 흡수하여 후기자어기로 넘어갔으며, 부화 후 15일에는 전장 $13.2{\pm}0.87mm$로 지느러미 기조가 모두 정수가 되어 치어기로 이행하였다. 부화 후 100일에는 전장 $49.2{\pm}4.29mm$로 성장하고 외부형태 및 체측반문이 성어와 비교적 유사하였다.

Egg development and early life history of Korean southern spine loach, Iksookimia hugowolfeldi, were observed in the present study. Eggs were obtained after injecting females with 0.5 mL/kg of Ovarprim. Eggs were artificially fertilized using the dry method in the laboratory. Number of spawned eggs were $1,933{\pm}530per$ individual. Mature eggs were slightly adhesive with light yellowish coloring, and they measured $1.35{\pm}0.03mm$ in diameter. Hatching of the embryo occurred 56 h (50%) after fertilization at water temperature $25^{\circ}C$, and newly hatched larvae were averaged of $5.6{\pm}0.18mm$ in total length. At 5 days after hatching, larvae averaged $7.8{\pm}0.31mm$ in total length and their yolk sacs had been completely absorbed. Beginning at 15 days after hatching, the fish entered the juvenile stage and reached $13.2{\pm}0.87mm$ in total length. At 100 days after hatching, the band patterns and external form of juvenile were similar to those of adults, and they averaged $49.2{\pm}4.29mm$ in total length.